Range Finding - How to estimate distance

I'm still doing simple things like estimating distance based on "how many football fields" it appears to be. Closer it matters less for a rifle, but with a pistol its good to know if that shot you just made is at 10 meters or 30 meters.

One trick I use when outdoors for telling how much daylight is high target and your thumb nail for example:

Extend your hand doing a big thumbs up in front of you.

Your entire thumbnail will cover a 12" target at a certain distance.
Half the height of your thumbnail will cover a 12" target at a certain distance.
A quarter of your thumbnail will cover a 12" target at a certain distance, and so on.

But we need to be more accurate.....


Range Estimation
By Pointman

There may come a time when you only get one shot at a target, and you may need for this "one shot" to get the job done. One of the most important considerations of long range marksmanship is range estimation. Proper ranging is critical because even the flattest shooting cartridges really start to drop after about 500 yards. Ranging errors of even 50 yards at extreme range can mean the difference between a hit and a miss. Therefore, if your team is set up as a sniper team, or if you have been assigned as the team designated marksman, it is a good idea to take the time to learn the basics.

Unassisted range-finding

The most common method of unassisted ranging is the "football field" method. Most people know this technique because it is fairly easy to visualize the length of 100 yards. Just estimate the number of football fields between you and the target and you have your range. A tip to use if the range is further than 500 yards is to pick a point halfway to the target, count the hundred yd increments to that point, then multiply by two.

If you are setting up an ambush site, you can simply pace the distance from your hide to the kill zone, of course this technique has serious drawbacks, such as giving away your position and the position of the planned kill zone.

You can use your map to estimate range if you know the exact location of you and the target. Just measure the distance with a protractor, however it's quite hard to be precise using this method.

You can use manmade structures if they are between you and the target and they are spaced at regular intervals. Utility poles are a good example, if there are 5 poles between you and your target, and you know that these poles are spaced at 75-yard intervals, then the range is 375 yards.

There are other methods you can use, but the ones outlined here are the most widely used and effective. A good rule of thumb to remember is that if you are using one of the unassisted methods, have more than one team member estimate the range or use more than one method if by yourself, and get an average.

Nothing new here, just some ideas from my brain housing group that I remember from my jarhead days. I hope someone will learn something that can help them one day.

Source:
http://www.alpharubicon.com/leo/rangeest.htm


How do I Estimate Ranges in Sniper Training?
By Scott Friedman, eHow Contributor

A scope is more accurate when the range to target is known.
Snipers are utilized on the modern battlefield just as often as tanks, fighter jets and satellites. The low-tech approach of a sniper often entails simple methods to get the job done. One area where simple methods come in handy is range estimation. While sniper teams may be issued laser range finders for some operations, they still train in a number of low technology methods of range estimation: an essential skill in the event of equipment failure.

Instructions

Paper Strip Method

1 Find your position on the terrain map of the area.

2 Pinpoint the position of the target on the terrain map of the area.

3 Tear a paper strip more than the length between your position on the map and the target's position on the map.

4 Mark the distance between your position and the target's position on the strip of paper with the pencil.

5 Place the marked paper strip over the bar scale of the map with one pencil mark over the zero and make note of the position of the other pencil mark. That value is your estimated range to target.

100 Meter Method

6 Measure out one hundred meters on the ground with a tape measure and mark each end with a stake in the ground. This distance is your point of reference to visualize one hundred meter increments, so observe it from different distances to become more familiar with it.

7 Determine the number of one hundred meter increments between you and the target to estimate the range for targets under five hundred meters.

8 Choose a point halfway between you and the target and determine the number of one hundred meter increments between you and that point. Then double that number to estimate the range of targets beyond five hundred meters.

Range Card Method

9 Choose objects within the target area which have a known distance such as landmarks or other features on the map. If possible, walk the terrain beforehand to determine the exact distances of some objects in the target area.

10 Fill out a range card with symbols of the known distance objects you have selected and place them on the card at the labeled distances.

11 Determine where your target is on the range card in relation to the other known distance objects when it appears in the target area. Mark the target on the range card and then read the estimated range to target.

Tips & Warnings
Practice makes perfect when it comes to range estimation. Try to spend as much time as possible attempting the above methods and then check the actual distances to monitor your improvement.

If handling firearms while training in range estimation, be sure to keep your firearm unloaded at all times unless you intend to shoot.

Source:
http://www.ehow.com/how_6836420_do-estimate-ranges-sniper-training_.html


From Combat Marksmanship Coach class of instruction 38, combat range estimation

1. ESTIMATING RANGE BY EYE

a. Unit of Measure. To determine the total distance to the target using this method, the Marine must visualize a distance of 100 meters on the ground, and then estimate how many of these units can fit between himself and the target.

1) The greatest limitation of the unit of measure method is that its accuracy is directly related to how much of the terrain is visible. This is particularly true at greater ranges. If a target appears at a range of 500 meters or more and only a portion of the ground between the Marine and the target can be seen, it becomes difficult to use the unit of measure method of range estimation with accuracy.

2) Proficiency in the unit of measure method requires constant practice. Throughout training, comparisons should be continually made between the range estimated by the Marine and the actual range as determined by pacing or other, more accurate measurement.

b. Appearance of Objects Method. To use this method, the Marine must be familiar with the sizes and details of personnel and equipment at known distances. Anything that limits the visibility (such as weather, smoke, or darkness) will also limit the effectiveness of this method. To use the appearance of objects method with accuracy, the Marine must be familiar with the characteristic details of objects as they appear at various ranges.

c. Rifle Front Sight Post Method. The area of the target that is covered by the front sight post of the rifle can be used to estimate range to the target. By comparing the appearance of the rifle front sight post on a target at known distances, the Marine can establish a mental reference point for determining range at unknown distances. Because the apparent size of the target changes as the distance to the target changes, the amount of the target that is covered by the front sight post will vary depending upon its range. In addition, the Marine's eye relief and perception of the front sight post will also affect the amount of the target that is visible. To utilize this method, use the following general guidelines:

a) The service rifle front sight post will cover the width of a man's chest or body at approximately 300 meters. If the target is less than the width of the front sight post, you should assume the target is in excess of 300 meters. Therefore, your BZO cannot be used effectively.

b) If the target is wider than the front sight post, you can assume that the target is less than 300 meters and can be engaged point of aim/point of impact using your BZO.

d. Visible Detail Method. When observing a target, The amount of detail seen at various ranges gives the Marine a good indication of the target's distance. He should study the appearance of a man when he is standing at a range of 100 meters. He fixes the man's appearance firmly in his mind, carefully noting details of size and the characteristics of uniform and equipment. Next, he should study the same man in a kneeling position and then in a prone position. By comparing the appearance of these positions at known ranges from 100 meters to 500 meters, the Marine can establish a series of mental images that will help determine range on unfamiliar terrain. He should also study the appearance of other familiar objects such as weapons and vehicles. The following general guidelines apply:

(1)At 100 yards/meters, the target can be Clearly observed in detail, and facial features can be distinguished.

(2)At 200 yards/meters, the target can be Clearly observed, although there is a loss of facial detail. The color of the skin and equipment is still identifiable.

(3) At 300 yards/meters, the target has a clear Body outline, face color usually remains accurate, but remaining details are blurred.

(4) At 400 yards/meters, the body outline is clear, but remaining detail is blurred.

(5) At 500 yards/meters, the body shape begins to taper at the ends. The head becomes indistinct from the shoulders.

(6) At 600 yards/meters, the body appears wedge-shaped with the appearance of no head.

e. Bracketing. This method of range estimation involves estimating the shortest possible distance and the greatest possible distance to the target. For example, the Marine might estimate that a particular target is as close as 300 meters away but could be as far as 500 meters away from his position. The estimated distances are then averaged to determine the estimated range to the target. In this example, the average of 300 meters and 500 meters is 400 meters.

f. Halving. The halving method of range estimation can be used to judge ranges out to 800 meters. Estimate the distance to the halfway point between your position and the target. Double that distance to get the total distance to the target. This method operates on the premise that it is easier to estimate 400 meters than 800 meters. The Marine must be careful when judging the distance to the halfway point. Any error made in judging the halfway distance will be doubled when estimating the total distance.

g. Combination of Methods. Most of the methods previously discussed require optimal conditions with regard to the target, terrain, and visibility. Therefore, it is likely that a more accurate estimate of range can be obtained by utilizing a combination of methods to support your estimate. For instance, two Marines could estimate range using different methods and compare their findings. The average of the two responses should be close to the range to the target.

2. FACTORS AFFECTING RANGE ESTIMATION

a. Nature of Target

1) An object with a regular outline such as a steel helmet, rifle, or vehicle on a clear day will appear to be closer than one with an irregular outline such as a camouflaged object.

2) A target that contrasts with its background will appear to be closer than one that blends in with its background.

3) A partially exposed object will appear to be farther away than it actually is.

4) A target will appear farther away if the target is smaller than the objects surrounding it.

b. Nature of Terrain

1) Upward sloping terrain gives the illusion of shorter distance.

2) Downward sloping terrain gives the illusion of greater distance.

3) Terrain with dead space will tend to make the target appear to be closer.

4) Smooth terrain such as sand, water, or snow will give the illusion of greater distance.

c. Light Conditions

1) The more clearly a target can be seen, the closer it appears to be. Smoke, fog, rain, or anything else that obscures vision will give the illusion of greater distance.

2)The position of the sun will also affect estimation by eye. When the sun is behind the viewer, it lights the target better so the target will appear to be closer. When the sun is directly beyond the target, the glare will give the illusion of greater distance.

d. Position. Targets appear farther away if the Observer is in a prone position.

3. POINT TARGETS AND HASTY SIGHT SETTING

a. Point Targets. Point targets are targets out to a range of 550 meters, the maximum effective range of the M16A2 service rifle. Targets the size of a man can be engaged with accuracy out to 550 meters with the service rifle.

b. Hasty Sight Setting. While a BZO is considered to be a true zero for 300 yards/meters, the Marine must be capable of engaging targets beyond this distance.

1) A hasty sight setting is a rear sight elevation setting that is temporarily applied to engage a target that is inside or outside of the BZO capability of the rifle. A setting of 8/3-2 at 200 yards for the M16A2 and 6/3-4 with the M16A4 (e.g., for precision shooting such as a head shot) is also considered a hasty sight setting.

2) The M16A2 service rifle sighting system design allows sight settings for distances out to 800 meters in 100 yard/meter increments. The M16A4 allows sight settings out to 600 meters/yards. This is accomplished by dialing in the appropriate range numeral on the rear sight elevation knob that corresponds to the range to the target.

3) For example, if the rear sight elevation knob is Set at 8/3 on the A2 or 6/3 on the A4 and a target appears at 500 meters, rotate the knob to the 5 setting to engage it. This is referred to as applying a hasty sight setting.

4. POINT OF AIM TECHNIQUE FOR ENGAGING TARGETS AT UNKNOWN DISTANCES.

When the distance to a target is beyond the BZO capability of the rifle and there is no time to adjust the sights, offset aiming techniques can be used. In the point of aim technique, predetermined points of aim sector the target horizontally. The tip of the front sight post held at shoulder level is considered one point of aim; the tip of the front sight post held at the top of the target’s head is considered two points of aim. To use the point of aim technique to engage a target beyond the rifle's BZO, the following guidelines apply:

a.When range to the target is estimated to be beyond 300 yards/meters out to 400 meters, hold one point of aim.

b. When the range to the target is estimated to be beyond 400 yards/meters out to 500 meters, hold two points of aim.

5. PRACTICAL APPLICATION FOR RANGE ESTIMATION

a. Exercise Setup

1) Set up the training site by placing several targets at various ranges out to 500 meters. Ensure targets are placed at accurate measurements so accurate student feedback can be provided.

2) Targets must be man-sized so that the instructional points of the lesson can be emphasized.

3) Camouflage or partially camouflage targets and equipment to provide realism. Place weapons with the targets to reinforce familiarity with what weapons and equipment look like at various distances.

4) Ensure Marines have their rifles so they can employ the rifle front sight post method of range estimation.

b. Range Estimating Methods

1) Unit of measure.

2) Appearance of objects.

a) Rifle front sight post method.

b) Visual detail method.

3) Bracketing.

4) Halving.

5) Combination of methods.

c. Factors Affecting Range Estimation

1) Nature of target.

2) Nature of terrain.

3) Light conditions.

4) Position.

Source:
Lets talk Range Estimation, how can one develop skills in this area?
http://www.ar15.com/archive/topic.html?b=9&f=1&t=230453

Further reading:

How to Make a Simple Rangefinder With Mirrors
By Jose Leiva, eHow Contributor
http://www.ehow.com/how_7857303_make-simple-rangefinder-mirrors.html

How to Make a Range Card
By Damien Thryn, eHow Contributor
http://www.ehow.com/how_6765856_make-range-card.html